Generally Speaking Resistor n Relays are opposite to each other?

Discussion in 'General Electronics Chat' started by raziiq, Nov 17, 2009.

  1. raziiq

    Thread Starter Active Member

    Dec 15, 2008
    Hi there.

    Just a noob in electronics. I have been reading lots of tutorials and trying to learn more and more about electrical circuits.

    Generally speaking, are resistors and Relays opposite to each other?

    i think this because resistors control (lessen) the flow of current in the circuit and relays enhance the voltage and current in the circuits using electromagnetic field.

    Is this right? Or am i missing something?
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    The two components are not really related. A resistor affects current in a circuit according to Ohm's law - E = IR. So current in a DC circuit is completely dependent on the value of R. In an AC circuit, you have impedances that also act as resistances, but that's a different question. Resistors use some inherently resistive substance to arrive at their value of resistance. Electromagnetism is not involved.

    A relay is an electromechanical switch. Placing a voltage across the coil results in a current that creates a magnetic field that pulls the armature and closes the contacts. That, in turn, can complete a separate circuit. It is most accurately viewed as a remotely controlled switch.
  3. russ_hensel

    Distinguished Member

    Jan 11, 2009
    And another way to look at a switch is a resistor whose resistance is either 0 or infinity.